Write the need of a standard unit.

An object travels 16m in 4s and then another 16m in 2s. What is the average speed of the object?

What is meant by uniform circular motion? Give two examples of uniform circular motion.

Pick out the concave and convex mirrors from the following and tabulate them Rear-view mirror, Dentist’s mirror, Torch-light mirror, Mirrors in shopping malls, Make-up mirror.

State the laws of refraction.

Write the uses of convex and concave mirros.

What are the factors required for change of state?

State the law of multiple proportions. Who stated this?

What are isotones? Give example.

An organism A which cannot move from one place to another makes a simple food B from the substances C and D available in the environment. This food is made in the presence of green coloured substance E present in organs F in the presence of light energy in a process called G Some of the simple food B also gets converted into a complex food H for storage purposes. This food gives blue-black colour with iodine solution?
(a) What is (i) organism A (ii) food B and food H?
(b) What are C and D?
(c) Name (i) green coloured substance E and organ F.
(d) What is the process G?

Why Vitamin D is called as 'Sunshine' Vitamin?

What is the amount of heat required to raise the temperature of 5 kg of iron from 30°C to 130°C? Specific heat capacity of iron = 483 Jkg^-1C^-1.

What is covalent bond?

What is water of crystallisation?

What is bit?

What is upthrust? State two factors on which the magnitude of buoyant force acting on an object immersed in liquid depends?

Write any two practical application of sound waves.

How are 'Galaxies' formed?

List out the characteristics of 'dye'.